This invention relates to a movable partition including at least one partition element and at least one, at least partially ferromagnetic, support post, in which the partition element has two upright edge sections which include magnetic systems extending essentially along the edge sections for joining the partition elements to at least one support post with the magnetic strip being flush on the support post.
At different times, the use of magnetic attraction has been described for joining partition elements, with or without support posts. A movable partition is described in Swiss patent specification 662601 in which the partition elements have edge sections along which one or more permanent magnets, or if appropriate electromagnets, co-operate with ferromagnetic parts of the support post, thus joining the partition elements to the post.
European patent applications 0178504 and 0807723 describe movable partitions having partition elements joined, not with support posts, but directly to one another and again using magnetic attraction. Also the corresponding partition elements have edge sections with several magnetic fittings distributed along their lengths.
Although considered satisfactory, the preceding known movable partitions suffer from a serious disadvantage. To guarantee a sufficiently stable assembly of partition elements with support posts, relatively strong magnets must be used. As a result, frequently in practice it is found that in the region of the join between partition elements and support posts a stray magnetic field is detectable up to considerable distances from the partition. This creates a risk to the security of data stored on machine readable data carriers if such data carriers are in the proximity of this kind of partition. Similarly, a risk applies for example to the safe functioning of heart pace-makers.
To solve a similar problem for the free end of a movable partition in which the individual elements are directly joined with one another without a support post, it was proposed in European patent application 0807723 to neutralise the magnetic field by means of a short-circuit element which is located in contact with magnetic pole socket of the magnet arrangement. However this insert is not only expensive for solving the problem but is also unsuitable when joining a partition element with a support post because a sufficiently high magnetic force must be provided to give the partition sufficient stability.
In the earliest known prior art, EP-0053933 A1, a movable partition has a magnetic strip on the support post for joining a partition element to the post. Indeed, this configuration of magnetic arrangement has two features which contribute to an improvement of the stray field problem compared to the prior art described above. This is because the field strength of the magnetic arrangement is confined to the region between the magnetic arrangements and the support post, in contrast to multiple magnets which would have a greatly enlarged area of effect, but without having a disadvantageous effect on stability of the erected partition. Furthermore, the stray field is further reduced by the flat arrangement of the magnetic strip on the support post. Nevertheless, with this well known movable partition, it is not out of the question that stray magnetic fields spread outwards with the disadvantages described above.
The object of the present invention is to provide a movable partition of the generally known type that provides improved protection of stored data on machine-readable data carriers and which minimises risk to persons with heart pace-makers.
The object is achieved by the present invention by providing magnetic strips embedded in a concave arcuate deep recess in the edge sections of the partition elements, the strips having unmagnetised edge areas. For example, with a 20 mm wide strip, only a 15 mm central area is magnetised and the remaining edge areas remain unmagnetised. Having such unmagnetised edge areas in combination with embedding the magnetic strips into deep grooves in the edge sections can clearly increase the security against stray fields, compared to the present state of the technology. At the same time, the arrangement provides for special circumstances, for example if the partition is accessible only at one side, or an asymmetric magnetisation of the magnetic strip in question. This particular manner of influencing the stray magnetic fields in a simple possible manner in the respective related applications, is a distinct advantage of the present invention which is not attained in partitions of the known kind.
A first preferred embodiment of the invention is characterised in that, at the free end of the edge section of a partition not joined with a support post, there is fitted an infill piece which neutralises the magnetic field of the respective magnetic strip. Such an infill piece is of ferromagnetic material. The surface of the infill piece facing towards the edge section has a curve which is complementary to the curve of the support post. In this manner, a flush contact of the respective magnetic strip with the infill piece is guaranteed resulting in the greatest possible cancellation of stray fields.
In an embodiment of the present invention, the support post preferably has a round cross-section and the magnetic strips preferably have a corresponding complementary concave arcuate outer surface. The round cross-section of the support post makes it possible for partition elements to be joined with it in any position. However, the support posts and the magnetic strips are not limited to that particular shape. For example, the support posts may have a polygonal (e.g. octagonal) cross-section whereby in this case the magnetic strips have a flat planar outer surface.
In a further preferred embodiment of the invention, the magnetic strips are flexible. It is particularly preferred that the magnetic strips are planar in the relaxed state whereby they are inserted under a bias or compression into a concave arcuate groove in the edge section. This is of particular advantage in relation to manufacture because the production of planar magnetic strips is considerably more cost effective than the production of arcuate magnetic strips. The cost advantage arises when a magnetic strip that needs to have an arcuate form in its final condition, as described above, is first produced as a planar magnetic strip and later, because of its flexibility, adopts a compressed arcuate shape when mounted in the edge section.
For secure mounting on the edge section the magnetic strip has at least one connection rib, most preferably on its rear, which fits into a groove of the respective edge section. Such a connection rib may have a swallow-tail shaped cross-section guaranteeing a secure mounting of the (if applicable compressed) magnetic strips in the respective groove of the edge section. The connection rib may be solid, hollow or split. Cross-sectional shapes other than the projecting swallow-tail shape, e.g. T-shape, can have similar advantages.
In a further preferred embodiment of the invention, the wall thickness of the support posts is throughout their length at least 1.2 mm ferromagnetic material. With this specification, a magnetic flux arises within the support posts of such a strength that stray fields, even under unfavourable conditions, are reduced to an insignificant level.
The edge sections have as reinforcement a reinforcement rib, preferably located at a rear portion, which fits into a complementary slot provided in an edge strip extending along the respective partition body of the partition element. In this way, the same shape of edge section can be readily mounted on different partition bodies, which is advantageous for a cost-effective modular system.
In another preferred embodiment of the invention, at least one safety member to be fitted afterwards is provided on a combined partition element/support post assembly for fixing the two parts together. It is significant that the safety member need not be permanently connected to the partition element or to the support post, but rather that it is fitted separately, if desired flexibly or removably, with the assembly of the partition element and support post. This is achieved by the safety member being secured as a final operation to a joined partition element/support post assembly. With this arrangement the partition element with its magnetic strip adhering to the support post need not be displaced relative to the support post in order to mount the safety member in its operative fixing position. To achieve this, the safety member can act as a clip-on security clip particularly mounted from above the edge section and the support post.